Mobile electronic devices, such as car radio devices, commonly have one or more cordless handsets “connected” thereto via a radio interface. This allows, for example, passengers to telephone using the cordless handsets. Naturally, the cordless handsets include a receiver capsule and a microphone capsule. The mobile electronic devices may also take the form of entertainment electronics to which other peripheral devices such as printers, input/output devices, etc. are connected via radio interfaces.
When such mobile electronic devices are used internationally, there are different national regulations for the permissible frequency range of the radio interface. For example, the ISM band in the frequency range from 2400 to 2483 MHz is used in various countries, but this frequency range can only be used to a limited extent in some countries, e.g. currently only from 2446 to 2454 MHz in France. It is also possible that only a selection of particular, precisely defined channels is permitted in some countries. The same considerations apply to the different regulations with regard to the maximum permissible transmitting power, e.g. 20 mW or 50 mW etc.
When crossing borders with a device, particularly in a motor vehicle or in a boat, it is necessary to adapt the frequency range or, respectively, the channels or the transmitting power of the radio interface to the national regulations in order to continue with operation of the mobile electronic device.
In the text which follows, the possible modes of the radio interface such as frequency/channel range, transmitting power, modulation etc. are combined in the term “operating configuration”.